Apparatus for bending vitreous tubing



y- 1940- c. A. BROWN ET AL 3, 58

I APPARATUS FOR BEIIDIIIG VITREOUS TUBING VIZ/22% 2 Sheets-Sheet 1 FiledNov. 18, 1937 m w .K n n 1 r M J V BAG, rmflkwww i w flvy Pb m8. 3 an R2 Sheets-Sheet C. A. BROWN ET AL APPARATUS FOR BENDING VITREOUS TUBINGFiled Nov.'l8, 1957 Brown, VanSickle V Inventors Car-l A. FPahk B.

Th Attorney.

July 23, 1940.

' Patented July 23, 1940 APPARATUS FOR BENDING VITREOUS TUBING Carl A.Brown, Chardon, and Frank B. Van Sickle, Lyndhurst, Ohio, assignors toGeneral Electric Company, a corporation of New York Application November18, 1937, Serial No. 175,196

10 Claims.

Our invention relates to apparatus for bending vitreous tubing or rodsand more particularly to a machine for automatically bending shortlengths of vitreous tubing or rods to a desired curvature.

Heretofore it has been the practice to bend vitreous tubing and rodsmanually with the assist:- ance of tools which usually consisted of aform, means for heating the tubing and perhaps tools for bending thetubing around the form. A very high degree of skill was required by theWorker and the operation was very slow and so costly as to prohibit theuse of curved tubing for envelops for incandescent lamps and most typesof discharge lamps.

The principal object of our invention is to increase the speed and lowerthe cost of bending both vitreous rod and vitreous tubing by providingan entirely automatic machine for this purpose. Another object of ourinvention is to increase the uniformity of the bent rod or tubing.

tube bending machine comprising our invention with transverse sectionsremoved therefrom to reduce the length of the drawing; Fig. 2 is a planview thereof; Fig. 3 is a section along line 3-3 of Fig. 2 in thedirection indicated; Fig. 4 is a vertical section along line 44- of Fig.2 on an enlarged scale and with portions removed as indicated and theremaining parts moved nearer together; and Fig. 5 is a piping diagramwith'all apparatus therein shown in section.

The machine shown in the drawing simultaneously operates on two lengthsof vitreous tubing I0 which are automatically fed from storage racks IIat the middle and on opposite sides of the machine. A tube I0 is takenfrom each rack H at the same instant and is placed before the end of oneof the spindles I2-l2 which are at that instant located farther to theright than shown in Figs. l and 2. Each spindle I2 is moved to the leftand passes into the interior of a tube H] which is then released by itssupporting means and is carried on said spindle l2 into the furnace oroven l3. The spindle l2 advances the tube I!) slowly through the furnacel3 so that the said tube is heated and softened before its end is in- 50serted between the rollers I l-15 and the roll H6. The spindle I2 isthen returned and the rotation of roll l6 carries the remainder of thetube l0 past the rollers I l-l5 which bend it to the curvature of saidroll. After an interval of time during which it cools down, the tube iscarried to the disof the four corners of the carriage.

charge conveyor belt I? located below saidroll 86 (Fig. 1). The machineis somewhat longer than shown and has sufficient structure to permitcarriage l8 on which both spindles ii are mounted to move the requireddistance. The movement 5 of'the carriage l8 controls the operationsof-the other portions of the machine which are controlled by' meanslocated along the path thereof and engaged bysaid carriage. The path ofmovement of the'carriage I8 is along a.track formed 10 by the channeledbars l9 and 20 which are engaged by the rollers 2|, 22 and 23 (Fig. 4)at each The rollers 2| and 22 engage the top and bottoms of the channelsin the bars 19 and 20 to hold the caris riage l8 vertically in positionand the rollers 23 engage the sides thereof to hold said carriage IS inproper alignment.

In each instance, the tube l0 rests upon the inclined rails 24 of a rackN (Fig. 3) and is pre-.- 20

vented from shifting longitudinally thereof by the end plates 25attached thereto. The inclined position 'of the rails 24 causes one ofthe tubes I0 in the rack II to roll into corresponding notches of a pairof wheels 26 on a shaft 21 which feed 25- a single tube Ill at intervalsby a 90 rotation thereof. The teeth in the wheels 26 are only longenough to catch the particular tube Ill resting thereagainst and lift itup over the top of said wheels 26 where it rolls down the backs ofthepre- 30 ceding teeth thereon and onto the upper edges of thevertically disposed plates 28 and 29 located adjacent the ends of rackH. The said plates are shown in lowered position in Fig. 1. The wheels26 are turned by the final movement 35 of the carriage l 8 in thepreceding cycle of operation during which it travels to the right andcarrice the finger 30 (Figs. 2 and 4) against one ofthe teeth of thewheel 3| (Fig. 2). The finger 30 pushes the tooth engaged by it back,causing the wheel 3| and shaft 32 on which said wheel 3| is mounted tobe turned slightly before the motion of carriage I8 is terminated. Theshaft 32 is supported by a bracket 33 extending from each of the'bars l9and 20 and is provided with bevel gears 34 on opposite ends thereofwhich mesh with the bevel gears 35 on the ends of both shafts 21. Theshafts 21 are supported by the brackets 36 attached to the bars l9 and20. 'Asshown in Figs. 2 and 4, the finger 30 is fastened to the pin 31which is mounted in the bearing 38 on the bracket 33 extending from thecarriage I8 and is prevented from turning in a counterclockwisedirection by the portion of bearing '38 joining its ends. A torsionspring 40 has its ends hooked in holes in the pin 31 and the bearing 38and allows the finger 39 and pin 31 to be turned back by the teeth onwheel 3| when the carriage I6 moves in the opposite (forward) direction.The rotation of the wheels 26 is limited to 90 degrees by a pin 4|(Figs. 1 and 3) which drops a corresponding movement of a piston 45 in acylinder 46 (Figs. 1, 2 and.5) to which the carriage I8 is connected'byrod 41, and results from the entrance of a liquid, preferably oil, intothe right hand end of said cylinder 46. The liquid is forced into saidcylinder 46 from a storage tank 48 by air introduced in said tank 48through a piston valve 49 and pipe 59 and passes through valves 5| and52 which control the rate of flow. At this time, a piston 53 (Fig. 5) invalve 49 is in the position shown and the compressed air is introducedtherein from a source (not shown) through pipe 54 (Figs. land 2)directly on top of the outer casing 55 thereof. From the pipe 54, theair passes into the longitudinal groove 56 in the top of the piston 53which conducts it to the angular passage 51 therein in alignment with aholein the casing 55 leading to pipe 59. The movement of the carriage I8is fairly rapid at this time since the hollow cores 58 in valves 5| and52 are turned so that the wider portion of the V slots 58 therein areopposite the openings in the bodies 59 which are both connected to thecylinder 46 through pipe 69.

During the first part of. the movement of the spindles |2|2, the tubes|9-l|| are held in position by the stop plate 6| (Figs. 1 and 3) whichis then located in front of the left ends thereof as shown in Fig. 3,but after spindles |2-|2 have passed into the tubes |9|9 so that inFig, 1. The plate 65 is mounted on a transverse shaft 66 which isconnected to shafts 63 by three arms 61 and a rod 66 so that a movementof plate causes corresponding movements of the supporting plates 28 and29. The

downward movement of the plates 28, 29 and 65 stretches the spring 69which is connected to a stationary part of the machine and one of thearms 61. The stop plate 6| is pivoted at 19 on arms extending from onepair of bearings 64 and is moved down by the pressure of a plate 1|,mounted on one of the shafts 63, thereagainst. The downward movement ofthe stop plate 6| stretches the spring 12 located between posts thereinand in supporting plate 29.

The rapid movement of the carriage l8 continues only until the tubesIll-l9 are completely within the furnace l3, whereupon a roller 4 gs.

therein.

2 and 3) which is attached to'the far side of the carriage l8 by meansof a bracket 15 engages a cam 16. The cam 16 is connected to the core 58of valve 5| through the shaft 11 and. when rotated by the roller 14,turns the core 58 so that flow of liquid through the valve 5| islessened and the carriage is moved more slowly. The

speed of movement of the carriage I8 is now .such that the tubes Ill-I0are retained, until preferably controlled automatically by means (notshown) in order to assure the most efficient operation of the machine.To facilitate a thorough and uniform heating of each of the tubes||l|ll, the said tubes are constantly rotated by the rotation .of thespindles |2--|2 which,

as shown in Fig. 4, are each mounted on ball bearings 19 and 89 in thecarriage l8 and are driven by an electric motor 8| mounted thereon.

The connection between the motor 6| and thespindles |2|2 is made througha worm gear 82 mounted on the motor shaft which meshes with gears 83 oneach of the spindles. Since excessive heat can be conducted back to thebearings in the carriage l8 in some instances, the spindles |2--|2' arecooled by a flow of air in the passage 84 in each spindle which connectsThe temperature of the furnace'l3 is to the chamber 85 in the carriage 8into which air is introduced through pipe 86.

By the time the forward end of each of the vitreous tubes Ill-I9 isheated sufficiently to permit bending, said end is carried between therollers |4-|5 and the form or roll i6 by the movements of. the carriage.|8. The rollers l4 and I5 and the roll l6 are preferably made of carbonso as not to stick to the tubes Ill-I0 and are provided withsemi-circular grooves in the faces thereof which conform to the exteriorshape of the tubes. Once a tube l9 passes be- "tween these rollers |4|5and the roll |6, it

is advanced by the rotation of the roll l6 which is mounted on a shaft81 and is turne'd in a counter-clockwise direction by a pulley 88mounted thereon. The shaft 81 is mounted in the frame 89 of the machinewhich also supports an electric motor 90 and speed reducer 9| whichoperates the pulley 98 through a belt 92 and pulley 93 on the shaft ofthe speed reducer 9|.

The roll I6 has a fixed relation to the roller M which is mounted on ahollow shaft 94 and is pressed down against roll l6 by springs 95located above slide blocks 96 on the opposite ends of shaft 94. -Theouter rims of the roller |4 ride in grooves 96' in the periphery of rolll6 at opposite sides of the semi-circular groove therein and does notdistort the tube Ill. The slide blocks 96 are located in ways in theframe 89 and engage one end of springs 95 which are retained in therequired state of compression by bolts 91. At the time the end of thetube In passes under the roller l4, the roller I5 is held in a raisedposition and does not contact the tubing II), but shortly thereaftersaid tube l0 passes below the roller l5 which is lowered so that the endof the tube is bent down into contact with roll I 6. The roller I5 ismounted on a hollow shaft98 which is supported by a lever 99 at eachside of the machine and is caused to move down by a piston I09 in acylinder ||l| which is connected to said levers 99 through a rod I02,link I03 and rod I94. The

' der 46 which pushes carriage I8 is directly responsible for themovement of the roller I5 since it reaches the limit of its movement atthis time and strikes the control pin I05 of a valve I06 which causesthe piston 53 within the valve 49 to shift and compressed air to passinto the cylinder IOI behind the piston I00. The carriage I8 moves thecontrol pin I05 back into the valve I06 (Fig. 5) thereby compressingthespring I01 and opening said valve I06 so. that air is bled from thespace behind the piston 53 through the pipe I08 and said valve I06. Inthis way, the piston 53 is shifted since the inflow of air into thespace referredto through the opening I09 in said piston 53 is notsuflicient to prevent the air pressure behind the other end thereof fromcausing it to move. 53, the compressed air passing, into the valve 49through the pipe 54 is conducted by the groove 56 and an angular passageH in the piston 53 to the opening in the valve casing 55 leading to pipeIII.- The pipe III conducts the compressed air to the cylinder IOI,which lowers the 'roller I as described, and to the forward end ofcylinthe piston 45 and carriage I8 back,

In order that the piston 45 can be moved by v its forward movement,carries a roller I I4 (Fig.

2) attached to the side thereof by the bracket II4, against a cam H6.The cam H5 is connected by a rod 5' to the core 58 of the valve,

52 which is turned so that the liquid in the cylinder 46 is permittedtoreturn to the storage tank 48 more rapidly than it passed therefr m.

The tube I6 is now supported solely by the rollers I4I5 and the roll I6and is advanced therebetween by the rotation of the roll' I6 which alsoadvances the bent or curved end under the rollers H6 and H6". Therollers II6'and 6' each have a semi-circular groove therein thatconforms'to the shape of the tubing I0 and are pressed against the rollI6 so that the rims thereof ride in the grooves 96' in said roll I6 andthe tubing I0 is held in place while cooling. The rollers H6 and II6"aresupported by hollow shafts H1 and H8 respectively which are mounted inslide blocks H9 and I? respectively in ways of the frame 89 at bothsides of the machine and are pressed against the roll "by springs HI andI22 located thereabove.

of the tubing is carried farther around with the roll I6 and'finally isengaged by the rollers I23 and I24 (Fig. 4) which hold it against rollI6 for an interval during which it is allowed to cool and is carriednearer to the discharge conveyor belt' I1. The roller I23 is supportedby an arm I25 which is pivoted on a bracket I26 extending from the frame89 of the machine, whereas roller I24 is supported by an armI21pivotally attached to the arm I25. The rollers I28 and I24 areretained in this position only during the interval the tube I0 isadvanced thereto since a followin tube I0 is then being transferred ontothe plates In the new location of the piston Dur ing the rotation of theroll I6 the forward end 28 and 29 (Fig; 1) and the bar 68 which movesthem into position toreceive said tubing I0 is against the control armI28 of a valve I29. The

' valve I29 (Fig. 5) controls the flow of compressed air into thecylinder I30 behind the piston III which is connected to the arm I21 byrod I32 and which swings said arm I21 so that the rollers,

duced into the valve I29 through pipe I34 and is conducted through thepassages in the valve body I35, the piston I36 and the pipe I31 to thecylinder I30. The control arm I28 of the valve I29 is pivoted in thevalve body I35 and moves the piston I36 down against the lifting forceof the compressed air within the passage in said piston I36. When theroll I 6 turns so far that the tube I0 is located on the lower portionthereof the rollers I23 andv I 24 are swung down and back from said rollI6 so that the tube I0 is partially carried and partially rolls downonto the conveyor belt I1. This action results from the bleeding of thecompressed air from the cylinder I80 through the valve I29 which permitsthe weight of the arms I25 and I21 to carry the rollers I28 and I24 downand is broughtabout by the downward movement of the plate 29 with theforward movement of the carriage I8 which raises the bar 68 from thecontrol arm I28 of the valve I28. The compressed air within the pistonI86 of the valve I29 raises it when the pressure is released fromthecontrol arm I28 so that a groove I36 around said piston I36 isbrought into alignment with the passage in the valve body I35 leading topipe I31 and the exhaust opening I39 in said body I35. In this way, thetube I0 is placed on the conveyor belt I1 so gently that all possibilityof distortion is eliminated and the finished tube I0 is carried awayfrom the machine by the conveyor I1. A partition I40 attached to the armI21 prevents the tubes. I0--I0 from touching each other when they areunloaded, This partition I40 passes up into a space between the rollsI6-I6 when the rollers I28 and I24 are in the raised position.

The return movement of the carriage I8 withdrawing the'spindles I2- -I2from the furnace I3 occursat a uniform rate until nearly the end of thestroke is reached whereupon the rollers 14 and H4 on opposite sidesthereof engage cams I and I42 respectively which adjust the valves 5|and 52. The cams HI and I42 are mounted on the rods 11 and H5 which areconnected to the cores 58-58 of the valves 5| and 52 and turn said cores5858 so that the flow of liquid through valve. 5'I ,is more rapid andthrough valve 52 is less rapid. This'adiustment sets the speedof theforward movement of the carriage I8 which is now brought about by thestriking of roller 4 thereon against valve I43. I bleeds the compressedair from the left end (Fig. 5') of the piston 53in valve 49 so that itshifts tothe p sition shown and compressed air is permitted to flowthrough passage 51 to the tank 48 to ac uate the carriage I8 as alreadydescribed. The roller II4 engages the pin I44 of valve I48 which compreses the spring I and separates the flanged portion of the pin I44 fromits seat on the valve body I46. The air allowed to escape The valve I48through the valve I43 passes thereto through pipe I41 and flows morerapidly from the valve casing 55 than it is permitted to flow in throughthe sure against the opposite end of the piston 53 causes it to shift.The air behind the left hand ,end' of the piston 45 in cylinder 46 isexhausted through pipe I I l, the transverse passage I49 in thepiston 53and the pipe I50 as succeeding repeat operations 'of the apparatus,which have been described, are brought about.

While we have shown and described certain novel features of theinvention, it will be understood that various omissions, substitutionsand changes in the form. and details of the device illustrated and inits use and operation may be made by those skilled in the artwithoutdeparting from the broad spirit and scope of the invention.

What we claim as new and desire to secure by LettersPatent of. theUnited States is: 1. Apparatus for bending vitreous tubing com prisingan oven, a form having a contour of the desired shape of the tubingrotatably mounted adjacent said oven, means for-advancing the tubinginto the oven to heat it to its softening temperature and for thenadvancing it into engagement with the form, means for pressing saidtubing against said form, and means for rotating said form to carry thetubing thereon past said pressing means and to cause it to be bent tothe shape of the form, the tube-engaging portions of said form andpressing means having opposed peripheral grooves of substantially thesame cross sectional shape as the'tubing to prevent distortion of itscross-sectional shape during the bending operation.

2. Apparatus for bending vitreous tubing comprising an oven, a roll thecurvature of the periphery of which corresponds to the desired shape ofthe tubing rotatably mounted adjacent said oven, means for advancing thetubing into said oven to heat it to its softening temperature and forthen advancing it into engagement with said roll, a plurality of rollerslocated adjacent the periphery of said roll for pressing said tubingagainst said roll, and means for rotating said prising an oven, a rollthe curvature of the periphery of which corresponds to the desired shapeof the tubing rotatably mounted adjacent said oven, means for advancingthe tubing into said oven to heat it to its softening temperature andfor then advancing it into engagement with said roll, a plurality ofrollers located adjacent theperiphery of said roll for pressing saidtubing against said roll, means for rotating said roll to carry thetubing thereon past said rollers to cause it to be bent to the curvatureof said roll,

and means for holding the tubing against said roll during furtherrotation thereof to allow said tubing to cool while it is still retainedin the desired shape, the tube-engaging portions of said roll androllers having opposed peripheral grooves of substantially the samecross-sectional shape as the tubing to prevent distortion of itscrosssectional shape during the bending operation.

4. Apparatus for bending vitreous tubing comprising an oven, a formhaving a contour of the desired shape of the tubing rotatably mountedadjacent said oven, means for supporting the tubing adjacent said oven,aspindle adapted to enter the tubing, means for carrying said spindle vinto the tubing and then further advancing it to carry said tubing intosaid oven to heat it to its softening temperature and then to carry anend of said tubing into engagement with said form, means for pressingsaid tubing into engagement with said form, and means for rotating saidform to carry the tubing thereon past said pressing means and cause itto be bent to the shape of said form.

5. Apparatus for bending vitreous tubing comprising an oven, a formhaving a contour of the desired shape of the tubing rotatably mountedadjacent said oven, means for supporting the tubing adjacent said oven,a spindle adapted to enter the tubing, a carriage for supporting saidspindle, a track for said carriage located adjacent said tubing holdingmeans and said oven, means for moving said carriage on its track tocarry the said spindle'into the tubing and then further advancing it tocarry said tubing into said oven to heat it to its softening temperatureand then to carry an end of said tubing into engagement with said form,means for pressing said tubing. into engagement with .said form, andmeans for rotating said form to carry the tubing thereon past saidpressing means andcause it to be bent to the shape of the form. 6.Apparatus for bending vitreous tubing comprising an oven, a form havinga contour of the desired shape of the. tubing rotatably, mounted-adjacent said oven, means forsupporting the gagement with'said form,means carried by said carriage for rotating said spindle to cause thetubing thereon to be rotated while it is in the oven, means for pressingthe tubing intoengagement with said form, and meansfor rotating saidform to carry the tubing thereon past said pressing means and cause itto be bent to the shape of said form. I

7. Apparatus for bending vitreous tubing comprising an oven, a formhaving a contour of the desired shape of the tubing rotatably mountedadjacent said oven, means for supporting the tubing adjacent said oven,a spindle adapted to enter the tubing, a carriage for supporting saidspindle, a track for said carriage located adjacent said tubing holdingmeans and said oven, means for moving said carriage on its track tocarry said spindle into the tubing and 'then further advancing it tocarry said tubing into said oven to heat it to its softening temperatureand thento carry an end of said tubing into engagement with said formcomprising a cylinder located adjacent said track and having a pistonthere'n attached tosaid carriage for moving it, a tank connected to oneend of said cylinder and containing a liquid, and means for supplyingair pressure to said tank to force liquid therefrom into said cylinderand against one side of the piston therein to advance the carriage andfor supplying air pressure to the other side of, said piston to retractthe carriage, means for pressing the tubing into engagement with saidform, and.

means for rotating said form to carry the tubing thereon past saidpressing means and cause it to be bent to the shapeof said form.

8. Apparatus for bending vitreous tubing comprising an oven, a formhaving a contour of the desired shape of the tubing rotatably mountedadjacent, said oveng means for supporting the tubing adjacent said oven,a spindle adapted to enter the tubing, a carriage forsupporting saidspindle, a track for said carriage located adjacent said tubing holdingmeans and said oven, means for moving said carriage on its track tocarry said spindle into the tubing and then further advance it to carrysaid tubing into said oven to heat it to its softening temperature andthen to carry an end of said tubing into engagement with said formcomprising a cylinder located adjacent said track and having a pistontherein attached to said carriage for moving it, a tank connected to oneend of said cylinder and con taining a liquid, means for supplying airpressure to said tank to force the liquid therefrom into said cylinderandagainst one side of the piston therein to advance the carriage andfor supplying air pressure to the other sideof said piston to retractthe carriage, a valve connected to said tank and to said cylinder forcontrolling the flow of liquid therebetween and means disposed along thepath of movement of said carriage and engaged thereby for adjusting theposition of said valve and varying the rate of movement of the saidcarriage, means for pressing the tubing into engagement with said form,and means for rotating said form to carry the tubing thereon past saidpressing means and cause it to be bent to the shape of said form.

9. Apparatus for bending vitreous tubing comprising an oven, a formhaving a contour of the desired shape of the tubing rotatably mountedadjacent said oven, means for supporting a plurality of tubings adjacentsaid oven, a plurality of spindles each adapted to enter one of saidtubings, a carriage for supporting said spindles, a track for saidcarriage located adjacent said tubing holding means and said oven, meansfor moving said carriage on its track, to carry each of said spindlesinto one of said tubings and then further advance it to carry the tubinginto said oven to heat it to its softening temperature and then to carryan end of the tubing into engagement with portions of said form, meansfor pressing tubings into engagement with said form, and means forrotating said form to carry the tubings thereon past said pressing meansand cause said tubings to be bent to the shape of the form.

10. Apparatus for bending vitreous tubing comprising an oven, aplurality of rolls the curvature of the peripheries of which correspondto the desired shape of the tubing rotatably mounted adjacent said oven,means for supporting a plurality of tubings adjacent said oven, aplurality of spindles each adapted to enter one tubing, a carriageforsupporting said spindles, a track for said carriage located adjacentsaid tubing holding means and said oven, means for moving said carriageon its track to carry each of said spindles into a tubing and thenfurther advance it to carry the tubing into said oven to heat it to itssoftening temperature and then' to carry an end of the tubing intoengagement with the periphery of one of said rolls, means carried bysaid carriage for rotating said spindles to cause the tubings thereon tobe rotated while in said oven, aplurality of rollers located adjacentthe periphery of said rolls for pressing the tubings into engagementtherewith, and means for rotating said rolls to carry-the tubingsthereon past said rollers and cause said tubings to be bent to thecurvature of said roll.

CARL A. BROWN. FRANK B. VAN SICKLE.

